Will give 5 stars if answered with an explanation too. a phone that normally costs $120 is on sale for $108. by what percent was the price marked down?

Can someone me with these two circle theorem questions asap?

The number of calories you burn depends on your weight. a 110-pound person burns 163 calories during 30 minutes of tennis. find the number of calories that a 190-pound person would burn during the same activity, assuming they burn calories at the same rate.

If x-1 and x+3 are the factors of x3+10x2+ax+b find a and b